class Restaurant:
    def __init__(self, restaurant_name, restaurant_type):
        self.name = restaurant_name
        self.type = restaurant_type
        self.number_served = 0

    def describe_restaurant(ss): # 也可以用别的变量名接收self，但一般默认为self，好辨识
        print(ss.name, ss.type)

    def open_restaurant(self, a):
        print(f"{self.name.title()} {a} opened.")

    def set_number_served(self, num):
        self.number_served = num

    def increment_number_served(self, add_num):
        self.number_served += add_num